/*
   Samba Unix/Linux SMB client library
   net serverid commands
   Copyright (C) Volker Lendecke 2010

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#include "includes.h"
#include "utils/net.h"
#include "lib/util/server_id.h"
#include "dbwrap/dbwrap.h"
#include "dbwrap/dbwrap_rbt.h"
#include "serverid.h"
#include "session.h"
#include "smbd/globals.h"
#include "source3/smbd/smbXsrv_session.h"
#include "smbd/smbXsrv_open.h"
#include "util_tdb.h"
#include "librpc/gen_ndr/ndr_open_files.h"

struct wipedbs_record_marker {
	struct wipedbs_record_marker *prev, *next;
	TDB_DATA key, val;
	const char *desc;
};

struct wipedbs_server_data {
	struct server_id server_id;
	const char *server_id_str;
	bool exists;
	struct wipedbs_record_marker *session_records;
	struct wipedbs_record_marker *tcon_records;
	struct wipedbs_record_marker *open_records;
};

struct wipedbs_state {
	struct db_context *id2server_data;
	struct {
		struct {
			int total;
			int existing;
			int disconnected;
		} server;
		struct {
			int total;
			int disconnected;
			int todelete;
			int failure;
		} session, tcon, open;
		int open_timed_out;
	} stat;
	struct server_id *server_ids;
	bool *server_exists;
	int idx;
	struct db_context *session_db;
	struct db_context *tcon_db;
	struct db_context *open_db;
	struct timeval now;
	bool testmode;
	bool verbose;
};

static struct wipedbs_server_data *get_server_data(struct wipedbs_state *state,
						   const struct server_id *id)
{
	struct wipedbs_server_data *ret = NULL;
	TDB_DATA key, val = tdb_null;
	NTSTATUS status;

	key = make_tdb_data((const void*)&id->unique_id, sizeof(id->unique_id));
	status = dbwrap_fetch(state->id2server_data, talloc_tos(), key, &val);
	if (NT_STATUS_IS_OK(status)) {
		ret = *(struct wipedbs_server_data**) val.dptr;
		TALLOC_FREE(val.dptr);
	} else if (NT_STATUS_EQUAL(status, NT_STATUS_NOT_FOUND)) {
		struct server_id_buf idbuf;

		server_id_str_buf(*id, &idbuf);

		ret = talloc_zero(state->id2server_data,
				  struct wipedbs_server_data);
		if (ret == NULL) {
			DEBUG(0, ("Failed to allocate server entry for %s\n",
				  idbuf.buf));
			goto done;
		}
		ret->server_id = *id;
		ret->server_id_str = talloc_strdup(ret, idbuf.buf);
		ret->exists = true;
		val = make_tdb_data((const void*)&ret, sizeof(ret));
		status = dbwrap_store(state->id2server_data,
				      key, val, TDB_INSERT);
		if (!NT_STATUS_IS_OK(status)) {
			DEBUG(0, ("Failed to store server entry for %s: %s\n",
				  idbuf.buf, nt_errstr(status)));
		}
		goto done;
	} else {
		struct server_id_buf idbuf;
		DEBUG(0, ("Failed to fetch server entry for %s: %s\n",
			  server_id_str_buf(*id, &idbuf), nt_errstr(status)));
		goto done;
	}
	if (!server_id_equal(id, &ret->server_id)) {
		struct server_id_buf idbuf1, idbuf2;
		DEBUG(0, ("uniq id collision for %s and %s\n",
			  server_id_str_buf(*id, &idbuf1),
			  server_id_str_buf(ret->server_id, &idbuf2)));
		smb_panic("server_id->unique_id not unique!");
	}
done:
	return ret;
}

static int wipedbs_traverse_sessions(struct smbXsrv_session_global0 *session,
				     void *wipedbs_state)
{
	struct wipedbs_state *state =
		talloc_get_type_abort(wipedbs_state,
		struct wipedbs_state);
	struct wipedbs_server_data *sd;
	struct wipedbs_record_marker *rec;
	TDB_DATA tmp;
	int ret = -1;

	assert(session->num_channels == 1);

	state->stat.session.total++;

	sd = get_server_data(state, &session->channels[0].server_id);
	if (sd == NULL) {
		goto done;
	}

	if (server_id_is_disconnected(&sd->server_id)) {
		state->stat.session.disconnected++;
	}

	rec = talloc_zero(sd, struct wipedbs_record_marker);
	if (rec == NULL) {
		DEBUG(0, ("Out of memory!\n"));
		goto done;
	}

	tmp = dbwrap_record_get_key(session->db_rec);
	rec->key = tdb_data_talloc_copy(rec, tmp);
	tmp = dbwrap_record_get_value(session->db_rec);
	rec->val = tdb_data_talloc_copy(rec, tmp);

	rec->desc = talloc_asprintf(
		rec, "session[global: %u wire: %llu]",
		session->session_global_id,
		(long long unsigned)session->session_wire_id);

	if ((rec->key.dptr == NULL) || (rec->val.dptr == NULL) ||
	    (rec->desc == NULL))
	{
		DEBUG(0, ("Out of memory!\n"));
		goto done;
	}

	state->session_db = dbwrap_record_get_db(session->db_rec);

	DLIST_ADD(sd->session_records, rec);
	ret = 0;
done:
	return ret;
}

static int wipedbs_traverse_tcon(struct smbXsrv_tcon_global0 *tcon,
				 void *wipedbs_state)
{
	struct wipedbs_state *state =
		talloc_get_type_abort(wipedbs_state,
		struct wipedbs_state);
	struct wipedbs_server_data *sd;
	struct wipedbs_record_marker *rec;
	TDB_DATA tmp;
	int ret = -1;

	state->stat.tcon.total++;

	sd = get_server_data(state, &tcon->server_id);
	if (sd == NULL) {
		goto done;
	}

	if (server_id_is_disconnected(&sd->server_id)) {
		state->stat.tcon.disconnected++;
	}

	rec = talloc_zero(sd, struct wipedbs_record_marker);
	if (rec == NULL) {
		DEBUG(0, ("Out of memory!\n"));
		goto done;
	}

	tmp = dbwrap_record_get_key(tcon->db_rec);
	rec->key = tdb_data_talloc_copy(rec, tmp);
	tmp = dbwrap_record_get_value(tcon->db_rec);
	rec->val = tdb_data_talloc_copy(rec, tmp);

	rec->desc = talloc_asprintf(
		rec, "tcon[global: %u wire: %u session: %u share: %s]",
		tcon->tcon_global_id, tcon->tcon_wire_id,
		tcon->session_global_id, tcon->share_name);

	if ((rec->key.dptr == NULL) || (rec->val.dptr == NULL) ||
	    (rec->desc == NULL))
	{
		DEBUG(0, ("Out of memory!\n"));
		goto done;
	}

	state->tcon_db = dbwrap_record_get_db(tcon->db_rec);

	DLIST_ADD(sd->tcon_records, rec);
	ret = 0;

done:
	return ret;
}

static int wipedbs_traverse_open(struct db_record *db_rec,
				 struct smbXsrv_open_global0 *open,
				 void *wipedbs_state)
{
	struct wipedbs_state *state =
		talloc_get_type_abort(wipedbs_state,
		struct wipedbs_state);
	struct wipedbs_server_data *sd;
	struct wipedbs_record_marker *rec;
	TDB_DATA tmp;
	int ret = -1;

	state->stat.open.total++;

	sd = get_server_data(state, &open->server_id);
	if (sd == NULL) {
		goto done;
	}

	if (server_id_is_disconnected(&sd->server_id)) {
		struct timeval disconnect_time;
		int64_t tdiff;
		bool reached;

		state->stat.open.disconnected++;

		nttime_to_timeval(&disconnect_time, open->disconnect_time);
		tdiff = usec_time_diff(&state->now, &disconnect_time);
		reached = (tdiff >= INT64_C(1000)*open->durable_timeout_msec);

		if (state->verbose) {
			TALLOC_CTX *mem_ctx = talloc_new(talloc_tos());
			enum ndr_err_code ndr_err;
			struct vfs_default_durable_cookie cookie;

			ndr_err = ndr_pull_struct_blob(
				&open->backend_cookie, mem_ctx, &cookie,
				(ndr_pull_flags_fn_t)ndr_pull_vfs_default_durable_cookie);
			if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
				d_printf("ndr_pull_struct_blob failed\n");
				ret = -1;
				goto done;
			}

			d_printf("open[%s/%s id: 0x%" PRIx32 "] disconnected at "
				 "[%s] %us ago with timeout of %us "
				 "-%s reached\n",
				 cookie.servicepath, cookie.base_name,
				 open->open_global_id,
				 nt_time_string(mem_ctx, open->disconnect_time),
				 (unsigned)(tdiff/1000000),
				 open->durable_timeout_msec / 1000,
				 reached ? "" : " not");
			talloc_free(mem_ctx);
		}

		if (!reached) {
			ret = 0;
			goto done;
		}
		state->stat.open_timed_out++;
	}

	rec = talloc_zero(sd, struct wipedbs_record_marker);
	if (rec == NULL) {
		DEBUG(0, ("Out of memory!\n"));
		goto done;
	}

	tmp = dbwrap_record_get_key(db_rec);
	rec->key = tdb_data_talloc_copy(rec, tmp);
	tmp = dbwrap_record_get_value(db_rec);
	rec->val = tdb_data_talloc_copy(rec, tmp);

	rec->desc = talloc_asprintf(
		rec, "open[global: %u persistent: %llu volatile: %llu]",
		open->open_global_id,
		(long long unsigned)open->open_persistent_id,
		(long long unsigned)open->open_volatile_id);

	if ((rec->key.dptr == NULL) || (rec->val.dptr == NULL) ||
	    (rec->desc == NULL))
	{
		DEBUG(0, ("Out of memory!\n"));
		goto done;
	}

	state->open_db = dbwrap_record_get_db(db_rec);

	DLIST_ADD(sd->open_records, rec);
	ret = 0;

done:
	return ret;
}

static int wipedbs_traverse_nop(struct db_record *rec, void *private_data)
{
	return 0;
}

static int wipedbs_traverse_fill_ids(struct db_record *rec, void *wipedbs_state)
{
	struct wipedbs_state *state = talloc_get_type_abort(
		wipedbs_state, struct wipedbs_state);

	TDB_DATA val = dbwrap_record_get_value(rec);

	struct wipedbs_server_data *sd = talloc_get_type_abort(
		*(void**)val.dptr, struct wipedbs_server_data);

	state->server_ids[state->idx] = sd->server_id;
	state->idx++;
	return 0;
}

static int wipedbs_traverse_set_exists(struct db_record *rec,
				       void *wipedbs_state)
{
	struct wipedbs_state *state = talloc_get_type_abort(
		wipedbs_state, struct wipedbs_state);

	TDB_DATA val = dbwrap_record_get_value(rec);

	struct wipedbs_server_data *sd = talloc_get_type_abort(
		*(void**)val.dptr, struct wipedbs_server_data);

	/* assume a stable traverse order for rbt */
	SMB_ASSERT(server_id_equal(&state->server_ids[state->idx],
				   &sd->server_id));
	sd->exists = state->server_exists[state->idx];

	if (sd->exists) {
		state->stat.server.existing++;
	}
	if (server_id_is_disconnected(&sd->server_id)) {
		state->stat.server.disconnected++;
	}

	state->idx++;
	return 0;
}

static bool serverids_exist(const struct server_id *ids, int num_ids,
			    bool *results)
{
	int i;

	for (i=0; i<num_ids; i++) {
		results[i] = serverid_exists(&ids[i]);
	}

	return true;
}


static NTSTATUS wipedbs_check_server_exists(struct wipedbs_state *state)
{
	NTSTATUS status;
	bool ok;
	int num_servers;

	status = dbwrap_traverse_read(state->id2server_data,
				      wipedbs_traverse_nop, NULL, &num_servers);
	if (!NT_STATUS_IS_OK(status)) {
		DEBUG(0, ("Failed to traverse temporary database\n"));
		goto done;
	}
	state->stat.server.total = num_servers;

	state->server_ids = talloc_array(state, struct server_id, num_servers);
	state->server_exists = talloc_array(state, bool, num_servers);
	if (state->server_ids == NULL || state->server_exists == NULL) {
		DEBUG(0, ("Out of memory\n"));
		goto done;
	}

	state->idx = 0;
	status = dbwrap_traverse_read(state->id2server_data,
				      wipedbs_traverse_fill_ids,
				      state, NULL);
	if (!NT_STATUS_IS_OK(status)) {
		DEBUG(0, ("Failed to traverse temporary database\n"));
		goto done;
	}

	ok = serverids_exist(state->server_ids, num_servers, state->server_exists);
	if (!ok) {
		DEBUG(0, ("Calling serverids_exist failed\n"));
		status = NT_STATUS_UNSUCCESSFUL;
		goto done;
	}

	state->idx = 0;
	status = dbwrap_traverse_read(state->id2server_data,
				      wipedbs_traverse_set_exists, state, NULL);
	if (!NT_STATUS_IS_OK(status)) {
		DEBUG(0, ("Failed to traverse temporary database\n"));
		goto done;
	}
done:
	TALLOC_FREE(state->server_ids);
	TALLOC_FREE(state->server_exists);
	return status;
}

struct wipedbs_delete_state {
	struct wipedbs_record_marker *cur;
	bool verbose;
	bool dry_run;
	size_t total;
	size_t num;
};

static void wipedbs_delete_fn(
	struct db_record *rec, TDB_DATA value, void *private_data)
{
	struct db_context *db = dbwrap_record_get_db(rec);
	struct wipedbs_delete_state *state = private_data;
	struct wipedbs_record_marker *cur = state->cur;
	NTSTATUS status = NT_STATUS_OK;

	state->total += 1;

	if (!tdb_data_equal(value, cur->val)) {
		DBG_ERR("Warning: record <%s> from %s changed,"
			"skip record!\n",
			cur->desc, dbwrap_name(db));
		return;
	}

	if (state->verbose) {
		d_printf("deleting %s\n", cur->desc);
	}

	if (!state->dry_run) {
		status = dbwrap_record_delete(rec);
	}

	if (!NT_STATUS_IS_OK(status)) {
		DBG_ERR("Failed to delete record <%s> from %s: %s\n",
			cur->desc,
			dbwrap_name(db),
			nt_errstr(status));
		return;
	}

	state->num += 1;
}

static int wipedbs_delete_records(struct db_context *db,
				  struct wipedbs_record_marker *records,
				  bool dry_run, bool verbose, int *count)
{
	struct wipedbs_delete_state state = {
		.verbose = verbose, .dry_run = dry_run,
	};

	if (db == NULL) {
		return 0;
	}

	for (state.cur = records;
	     state.cur != NULL;
	     state.cur = state.cur->next) {

		NTSTATUS status = dbwrap_do_locked(
			db, state.cur->key, wipedbs_delete_fn, &state);

		if (!NT_STATUS_IS_OK(status)) {
			DBG_ERR("dbwrap_do_locked failed for record <%s> "
				"from %s\n",
				state.cur->desc,
				dbwrap_name(db));
		}
	}

	if (verbose) {
		d_printf("Deleted %zu of %zu records from %s\n",
			 state.num,
			 state.total,
			 dbwrap_name(db));
	}

	if (count) {
		*count += state.total;
	}

	return state.total - state.num;
}

static int wipedbs_traverse_server_data(struct db_record *rec,
					void *wipedbs_state)
{
	struct wipedbs_state *state = talloc_get_type_abort(
		wipedbs_state, struct wipedbs_state);
	bool dry_run = state->testmode;
	TDB_DATA val = dbwrap_record_get_value(rec);
	int ret;
	struct wipedbs_server_data *sd = talloc_get_type_abort(
		*(void**)val.dptr, struct wipedbs_server_data);

	if (state->verbose) {
		d_printf("Server: '%s' %s\n", sd->server_id_str,
			 sd->exists ?
			 "exists" :
			 "does not exist, cleaning up...");
	}

	if (sd->exists) {
		return 0;
	}

	ret = wipedbs_delete_records(state->session_db, sd->session_records,
				     dry_run, state->verbose,
				     &state->stat.session.todelete);
	state->stat.session.failure += ret;

	ret = wipedbs_delete_records(state->tcon_db, sd->tcon_records,
				     dry_run, state->verbose,
				     &state->stat.tcon.todelete);
	state->stat.tcon.failure += ret;

	ret = wipedbs_delete_records(state->open_db, sd->open_records,
				     dry_run, state->verbose,
				     &state->stat.open.todelete);
	state->stat.open.failure += ret;

	return 0;
}

static int net_serverid_wipedbs(struct net_context *c, int argc,
				const char **argv)
{
	int ret = -1;
	NTSTATUS status;
	struct wipedbs_state *state = talloc_zero(talloc_tos(),
						  struct wipedbs_state);

	if (c->display_usage) {
		d_printf("%s\n%s",
			 _("Usage:"),
			 _("net serverid wipedbs [--test] [--verbose]\n"));
		d_printf("%s\n%s",
			 _("Example:"),
			 _("net serverid wipedbs -v\n"));
		return -1;
	}

	state->now = timeval_current();
	state->testmode = c->opt_testmode;
	state->verbose = c->opt_verbose;

	state->id2server_data = db_open_rbt(state);
	if (state->id2server_data == NULL) {
		DEBUG(0, ("Failed to open temporary database\n"));
		goto done;
	}

	status = smbXsrv_session_global_traverse(wipedbs_traverse_sessions,
						 state);
	if (!NT_STATUS_IS_OK(status)) {
		goto done;
	}

	status = smbXsrv_tcon_global_traverse(wipedbs_traverse_tcon, state);
	if (!NT_STATUS_IS_OK(status)) {
		goto done;
	}

	status = smbXsrv_open_global_traverse(wipedbs_traverse_open, state);
	if (!NT_STATUS_IS_OK(status)) {
		goto done;
	}

	status = wipedbs_check_server_exists(state);
	if (!NT_STATUS_IS_OK(status)) {
		goto done;
	}

	status = dbwrap_traverse_read(state->id2server_data,
				      wipedbs_traverse_server_data,
				      state, NULL);
	if (!NT_STATUS_IS_OK(status)) {
		DEBUG(0, ("Failed to traverse db: %s\n", nt_errstr(status)));
		goto done;
	}

	d_printf("Found %d serverids, %d alive and %d disconnected\n",
		 state->stat.server.total,
		 state->stat.server.existing,
		 state->stat.server.disconnected);
	d_printf("Found %d sessions, %d alive and %d disconnected"
		 ", cleaned up %d of %d entries\n",
		 state->stat.session.total,
		 state->stat.session.total - state->stat.session.todelete,
		 state->stat.session.disconnected,
		 state->stat.session.todelete - state->stat.session.failure,
		 state->stat.session.todelete);
	d_printf("Found %d tcons, %d alive and %d disconnected"
		 ", cleaned up %d of %d entries\n",
		 state->stat.tcon.total,
		 state->stat.tcon.total - state->stat.tcon.todelete,
		 state->stat.tcon.disconnected,
		 state->stat.tcon.todelete - state->stat.tcon.failure,
		 state->stat.tcon.todelete);
	d_printf("Found %d opens, %d alive, %d disconnected and %d timed out"
		 ", cleaned up %d of %d entries\n",
		 state->stat.open.total,
		 state->stat.open.total - state->stat.open.todelete
		 - (state->stat.open.disconnected - state->stat.open_timed_out),
		 state->stat.open.disconnected,
		 state->stat.open_timed_out,
		 state->stat.open.todelete - state->stat.open.failure,
		 state->stat.open.todelete);

	ret = 0;
done:
	talloc_free(state);
	return ret;
}

static int net_serverid_exists(struct net_context *c, int argc,
			       const char **argv)
{
	struct server_id pid;
	bool ok;

	if ((argc != 1) || (c->display_usage)) {
		d_printf("Usage:\n"
			 "net serverid exists <serverid>\n");
		return -1;
	}

	pid = server_id_from_string(get_my_vnn(), argv[0]);
	ok = serverid_exists(&pid);

	if (ok) {
		d_printf("%s exists\n", argv[0]);
	} else {
		d_printf("%s does not exist\n", argv[0]);
	}

	return 0;
}

int net_serverid(struct net_context *c, int argc, const char **argv)
{
	struct functable func[] = {
		{
			"wipedbs",
			net_serverid_wipedbs,
			NET_TRANSPORT_LOCAL,
			N_("Clean dead entries from temporary databases"),
			N_("net serverid wipedbs\n"
			   "    Clean dead entries from temporary databases")
		},
		{
			"exists",
			net_serverid_exists,
			NET_TRANSPORT_LOCAL,
			N_("Show existence of a serverid"),
			N_("net serverid exists <id>")
		},
		{NULL, NULL, 0, NULL, NULL}
	};

	return net_run_function(c, argc, argv, "net serverid", func);
}